A102856 Sum of 1 or 2 distinct tetrahedral numbers.

0, 1, 4, 5, 10, 11, 14, 20, 21, 24, 30, 35, 36, 39, 45, 55, 56, 57, 60, 66, 76, 84, 85, 88, 91, 94, 104, 119, 120, 121, 124, 130, 140, 155, 165, 166, 169, 175, 176, 185, 200, 204, 220, 221, 224, 230, 240, 249, 255, 276, 285, 286, 287, 290, 296, 304, 306

Offset

1,3

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

N:= 1000: # for terms <= N
R:= 0:
for i from 1 do
  ti:= i*(i+1)*(i+2)/6;
  if ti > N then break fi;
  for j from 0 to i-1 do
     v:= ti + j*(j+1)*(j+2)/6;
     if v > N then break fi;
     R:= R, v;
  od;
od:
sort(convert({R}, list)); # Robert Israel, Jan 16 2024

Mathematica

Module[{nn=12, tetra}, tetra=Table[(n(n+1)(n+2))/6, {n, nn}]; Union[ Total/@ Subsets[tetra, 2]]] (* James C. McMahon, Jan 12 2024 *)

Crossrefs

Cf. A000292, A010329, A104246, A102795-A102806, A102855, A102857, A102858, A334013.

Sequence in context: A131855 A102858 A102857 * A285135 A037353 A269003

Adjacent sequences: A102853 A102854 A102855 * A102857 A102858 A102859

Keyword

nonn

Author

Jud McCranie, Mar 01 2005

Extensions

a(1) = 0 prepended by James C. McMahon, Jan 15 2024

Status

approved